Skinny or curvy

What does the modeling business want? First models had to be skinny, that went form heroin chic to anorexic and even models who died because of the size zero standard on the catwalk. And then there was that big change. I think it started a couple of years ago back in Spain where girls with a BMI less than 18 where boycotted.
Now days the plus size models are the rising stars. Every high fashion magazine brings out an issue dedicated to them. It's good to see that things can change and that curves are appreciated again just like back in the golden years of Hollywood.
What I don't get is one thing, why only size zero and plus size models. What about the woman who do not have that size. A skinny models has to have (in Dutch sizes) size 32-34. The size of a plus size model starts at (in Dutch sizes) 44. So what about the sizes between that? I don't understand. Why is it almost always like you can only go left or right? If you see it in black and white, you have or to loose weight or gain a lot if you have a (Dutch size) size 38 like me. There are a lot of Campaigns that says that a woman can be who she is and more stuff like that. I think it will work if the modeling industry decides that all sizes are ok. Not only a skinny Victoria Beckham or a Curvy Christina Hendricks, but all of us, people like you and me.